The present invention relates generally to inductor isolation, and more particularly, to an inductive arrangement and method for isolating planar inductors using a magnetic disk to minimize ground plane effects.
Typically, characteristics of inductive components are severely degraded when the inductor is in close proximity to another piece of metal, such as ground planes. In particular, the inductance value can decrease by over 65%. This results in a significant decrease in component Q. Consequently, component surface area must increase, thus increasing the overall circuit size. This is detrimental to applications requiring high power densities.
Current approaches mitigate ground plane effects in several ways. One approach is to eliminate the ground plane altogether and replace it with a ground trace. Another approach requires holes or cut-outs in a portion of ground plane located directly above the affected component. However, these two approaches prove to be detrimental to the electrical performance of the circuit. The third approach is to separate the ground plane from the inductor by a relatively large distance, which is over three times the required thickness of the circuit substrate. This is undesirable for low profile, high power density applications where minimizing circuit volume is critical.
Accordingly, it is an objective of the present invention to provide for an inductive arrangement and method for isolating planar inductors that overcomes the limitations of prior art approaches. It is a further objective of the present invention to provide for an inductive arrangement and method for isolating planar inductors using a magnetic disk to minimize ground plane effects.